diff --git a/config/site_settings.yml b/config/site_settings.yml
index 710b194cc4a..bb06873f237 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -512,7 +512,7 @@ login:
     regex: "^[a-z0-9]+$"
   linkedin_oidc_client_secret:
     default: ""
-    regex: "^[a-zA-Z0-9]+$"
+    regex: "^[a-zA-Z0-9_=\\.]+$"
     secret: true
   auth_skip_create_confirm:
     default: false